Power Frequency Magnetic Field Background
Electronic products are often subjected to magnetic fields at AC mains frequencies. These fields are frequently produced in the vicinity of power transformers and can cause problems with video displays, Hall effect sensors, and other electronic products having a sensitivity to magnetic fields.
Electronic Products are tested for immunity to power frequency magnetic fields to insure their continued reliable operation when placed in service. The European Union’s EMC Directive currently mandates power frequency magnetic field testing for certain categories of equipment as a condition for obtaining the CE Mark before shipping products to member states of the European Union.
Generic Immunity, Product and Product Family Standards require that Power Frequency Magnetic Field tests be performed in accordance with Basic EMC Standards: IEC 61000-4-8 and EN 61000-4-8. Thermo KeyTek’s Application Note, “EMC Standards Overview,” provides an overview of European Standards for electromagnetic compatibility, describes how the Standards relate to one another, and list sources for procuring copyrighted documents.
Basic EMC Standard
The Basic EMC Standard for Power Frequency Magnetic Field defines methods of generating consistently reproducible magnetic fields for test purposes. Although higher magnetic field levels are described, compliance to the Generic Immunity Standard for residential and commercial products is 1A/m or 3A/m. Currently applicable only to apparatus containing devices susceptible to magnetic fields, testing of other products may be required to make that determination. While the Basic EMC Standard specifies how to perform Power Frequency Magnetic Field testing, the Generic, Product and Product Family Standards specify the test levels and pass/fail performance criteria.
Power Frequency Magnetic Field testing is required for products that could be affected by magnetic fields, including CRTs and Hall Effect Sensors and is strongly recommended for all products.
|EN 50082-1||Generic Immunity – Residential, Commercial and Light Industrial||N/A|
|Generic Immunity – Residential, Commercial and Light Industrial||3A/m|
|EN 50082-2||Generic Immunity – Industrial Environment||30A/m|
|Generic Immunity – Industrial Environment||30A/m|
|EN 55104||Immunity for Household Appliances, Tools and Similar Apparatus||N/A|